The hard encryption keyboard of a bank self-service equipment bears works of inputting and encrypting a bank password of a user, and thus a working key and a master key of the bank are stored in a core processing part of the keyboard. For an unspeakable purpose, some criminals usually jimmy or poke the keyboard to steal the user password and even to decrypt the working key and master key of the bank in order to steal bank information, which threatens the security of information and money of the user and the bank directly.
The encryption keyboard is generally provided with a poking detection and protection structure and a poking detection and protection circuit. When the keyboard is subjected to a physical poking, the poking detection and protection circuit outputs a self-destruction signal to realize a self-destruction function of the encryption keyboard, so as to prevent the criminals from stealing bank information.
The Chinese patent application CN201489599U discloses an encryption keyboard and a poking detection and protection structure thereof. The disclosed encryption keyboard includes an anti-peeping cover, an anti-peeping cover bracket, a poking detection and protection net and conductive adhesive. The poking detection and protection net is received inside the anti-peeping cover, and is clamped and fixed between the anti-peeping cover and the anti-peeping cover bracket by the anti-peeping cover bracket, and is provided with a plurality of first gold fingers thereon. A main control board in the keyboard is provided with a poking protection circuit provided with a plurality of second gold fingers thereon. The first gold fingers and the second gold fingers are electrically connected via the conductive adhesive. The anti-peeping cover bracket is provided with a cavity at the position corresponding to the first gold fingers, and the conductive adhesive is filled in the cavity.
The above poking detection and protection net is a double-layer flexible circuit board, and the periphery edges thereof is folded such that the poking detection and protection net is formed into a cuboid shape and covers a main control circuit board required to be protected. Thus, there is no gap between the main control circuit board and the exterior, which achieves the anti-poking purpose. An anti-poking detection circuit is provided in the flexible circuit board and is covered with detection wirings by using the maze wiring method. The anti-poking detection circuit is directed onto a surface of the flexible circuit board by a gold finger, and is electrically connected with the control circuit of the main control board for realizing the self-destruction function via the gold finger. When the flexible circuit board is subjected to the physical poking, a self-destruction signal can be output by making short circuit between any two adjacent wirings or breaking any one wiring. Thus, the self-destruction function of the encryption keyboard is realized, and sensitive information is deleted immediately, so as to prevent the criminals from stealing bank information.
This technology has following disadvantages.
First, since the flexible circuit board can only be made with two layers, with an outer layer being ground layer without wiring and an inner layer being maze wiring layer, and the gold fingers at the connection between the flexible circuit board and the protected main control circuit board are relatively thick, the criminals can easily scrape the ground layer and connect the gold fingers at the two ends of the inner layer. In this way, the whole maze wiring layer fails to function by making short circuit between the wirings, and thus loses the protective effect.
Second, Because of the flexibility of the flexible circuit board, the criminals may only tightly press the connection wires between the flexible circuit board and the protected circuit board, and then turn over the other parts of the circuit board to expose the protected circuit and to thereby lose the protective effect.
Therefore, it is very important to provide an encryption keyboard having a multi-directional anti-poking detection and protection system.